Locking device for the carriage of a drawing apparatus

ABSTRACT

A locking device for the carriage of a drawing apparatus, in which the base of the carriage has a groove therein, extending laterally with respect of the longitudinal axis of the base, with the groove receiving a slide. The slide has its opposite end portions bent in the same direction, with one of the opposite end portions acting as a stop adapted to engage a guideway along which the carriage is adapted to travel. Mounted intermediate of the bottom of the groove and slide is a bent leaf spring having first end portion thereof secured to the slide and a second end portion thereof extending through an opening in the slide and acting as another stop, also adapted to engage the guideway. The other one of the opposite end portions of the slide supports means for selectively clamping the guideway between two stops, and such means is associated with the second end portion of the spring.

United States Patent Perminov [1.51 3,656,238 [4 1 Apr. 18, 1972 [54] LOCKING DEVICE FOR THE 787,618 6/1968 Canada ..33/79R Primary Examiner-Harry N. Haroian Attorney-Holman & Stern [57] ABSTRACT A locking device for the carriage of a drawing apparatus, in which the base of the carriage has a groove therein. extending laterally with respect of the longitudinal axis of the base, with the groove receiving a slide. The slide has its opposite end portions bent in the same direction, with one of the opposite end portions acting as a stop adapted to engage a guideway along which the carriage is adapted to travel. Mounted intermediate of the bottom of the groove and slide is a bent leaf spring having first end portion thereof secured! to the slide and a second end portion thereof extending through an opening in the slide and acting as another stop, also adapted to engage the guideway.

The other one of the opposite end portions of the slide sup ports means for selectively clamping the guideway between two stops, and such means is associated with the second end portion of the spring.

1 Claims, 2 Drawing Figures LOCKING DEVICE FOR THE CARRIAGE OF A DRAWING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to drawing apparatus, and, more particularly, to locking devices for the carriages of drawing apparatus.

A locking device constructed in accordance with the present invention can be most expediently employed in drawing apparatus of the widely known coordinate type, in which a carriage is adapted to travel along a substantially flat guideway.

Widely known in the art are locking devices for the carriages of drawing apparatus, which include a pair of relatively movable stops mounted on the base of the carriage. The guideway extends intermediate of the stops and is adapted to have its opposite non-working surfaces clamped between the stops, when the carriage is to be locked in respect of the guideway.

For the stops to be moved relative to one another, when the carriage is to be thus locked, the stops are interconnected by a clamping means including either a screw-type or an eccentrictype manually actuated mechanism positioned substantially outside the main body of the carriage.

A disadvantage of these known locking devices is the fact that such a locking device increases the overall dimensions of the carriage, chiefly because the stops thereof are situated adjacent to the non-working plane surfaces of the guideway.

It is an object of the present invention to eliminate this disadvantage.

SUMMARY OF THE INVENTION The main object of the present invention is to provide a locking device for the carriage of a drawing apparatus, in which the stops adapted to clamp therebetween the guideway of the carriage are positioned adjacent to the working surfaces of the guideway.

This object is accomplished in a locking device for the carriage of a drawing apparatus, comprising a pair of movable stops mounted on the base of the carriage, with the stops being associated with means for clamping therebetween the guideway along which the carriage is adapted to travel, when the carriage is to be locked in respect of the guideway, in which locking device, in accordance with the present invention, the base of the carriage has a groove therein extending laterally in relation to the longitudinal axis of the base, with the groove receiving a slide having its opposite end portions bent in the same direction, with one of the opposite end portions acting as a stop adapted to engage a first working surface of the guideway and the other of the opposite end portions supporting the clamping means, there being situated intermediate the bottom of the groove and the slide a bent leaf spring having a first end portion thereof secured to the slide and a second end portion thereof extending through an opening in the slide and acting as another stop adapted to engage the other working surface of the guideway and associated with the clamping means.

The present locking device for the carriage of a drawing apparatus features relatively small dimensions and is structurally simple, and, therefore, requires a comparatively small amount of labor for its manufacture.

Other objects and advantages of the present invention will be made apparent in the following detailed description of a locking device for the carriage of a drawing apparatus embodying the invention, with reference being had to the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a general plan view of the carriage of a drawing apparatus, incorporating a locking device constructed in accordance with the invention; and

FIG. 2 is a view taken along line II-II of FIG. 1, the view looking in the direction of the arrows.

Referring to the drawings, a base 1 (FIG. 1) of a carriage 2 of a drawing apparatus has mounted thereon two pairs of rollers 3 engaging a guideway 4 for reciprocation of the carriage along the guideway. The base 1 is provided with a groove 5 of dovetail-shape in cross-section. The groove 5 is positioned substantially centrally of the base 1 and extends perpendicularly to the longitudinal axis 6 of the base 1.

The groove 5 receives a slide 7 having its end portions 8 and 9 displaced or bent at substantially right angles to the base thereof in the same direction.

The end portion 8 of the slide 7 is positioned adjacent to one of the two opposite working surfaces of the guideway 4 and acts as a stop. The other bent end portion 9 is adapted to support a clamping means which includes a screw 10 extending through a threaded opening provided in the bent end portion 9.

Situated intermediate of the bottom wall of the groove 5 and the slide 7 is a bent leaf spring 11. A first end portion 12 of the leaf spring 11 is rigidly secured by a rivet or the like to the slide 7 and the arcuately bent portion of the spring I] abuts against the bottom wall of the groove 5, with second end portion 13 thereof extending through an opening 14 cut through the slide 7.

The end portion 13 of the spring 11 acts as a second stop positioned adjacent to the other working surface of the guideway 4, which is opposite to the first working surface.

In order to protect the respective working surfaces of the guideway 4 from being mechanically damaged, the stops 8 and 13 are equipped with elastic pads 15.

The present locking device for the carriage of a drawing apparatus operates as follows:

When the screw 10 is rotated, e.g. in a clockwise direction, the end portion thereof exerts a pressure upon the end portion 13 of the leaf spring II. Under this pressure, the spring 11 unbends, and the arcuate portion thereof abuts against the bottom wall of the groove 5. When the stop 13 engages the adjacent working surface of the guideway 4, the continued rotation of the screw 10 causes the slide 7 move in the groove 5 against the friction forces, until the stop 8 engages the adjacent working surface of the guideway 4, which is opposite to the first-mentioned surface, and thus the slide 7 becomes positively jammed in the groove 5. a

In this way, the carriage 2 is locked in a desired position relatively to the guideway 4.

When the screw 10 is rotated in the opposite direction, i.e. in a counter-clockwise direction, the slide 7 is released in the groove 5, and the stops 8 and 13 no longer retain the carriage 2, whereby the carriage can be freely moved along the guideway 4.

The carriage of a drawing apparatus, incorporating the present locking device, features a relatively small size, is easy to manufacture and ensures reliable locking thereof in any desired position along the guideway.

What is claimed is:

l. A carriage for a drawing apparatus adapted for reciprocation along a guideway, comprising a base and a plurality of roller means mounted on said base cooperable with the guideway for the reciprocation of the carriage along the 0 guideway, in combination with a locking device for said carriage, said carriage having a groove in said base thereof extending laterally with respect to the longitudinal axis of said base; a slide received in said groove, said slide having first and second end portions bent in the same direction, said first end 5 portion acting as a stop adapted to engage said guideway; a

bent leaf spring situated intermediate of the bottom of said goove and said slide, the first end portion of said spring being secured to said slide and a second end portion thereof extending through an opening in said slide and serving as another stop adapted to engage said guideway; means for clamping selectively said guideway between said first-mentioned stop and said another stop for locking said carriage with respect of said guideway, and said clamping means being supported by said second end portion of said slide and associated with said another stop of said spring.

i= a a 

1. A carriage for a drawing apparatus adapted for reciprocation along a guideway, compRising a base and a plurality of roller means mounted on said base cooperable with the guideway for the reciprocation of the carriage along the guideway, in combination with a locking device for said carriage, said carriage having a groove in said base thereof extending laterally with respect to the longitudinal axis of said base; a slide received in said groove, said slide having first and second end portions bent in the same direction, said first end portion acting as a stop adapted to engage said guideway; a bent leaf spring situated intermediate of the bottom of said goove and said slide, a first end portion of said spring being secured to said slide and a second end portion thereof extending through an opening in said slide and serving as another stop adapted to engage said guideway; means for clamping selectively said guideway between said first-mentioned stop and said another stop for locking said carriage with respect of said guideway, and said clamping means being supported by said second end portion of said slide and associated with said another stop of said spring. 